1. Field of the Invention
This invention relates to an apparatus for opening and closing railroad hopper car discharge doors. More particularly, the invention relates to an air powered apparatus which may be installed on existing railroad hopper cars, without extensive modification thereof, to improve the operation of opening and closing the car discharge doors.
2. Description of the Related Art
Railroad hopper cars normally include a hopper body supported upon an undercarriage. The hopper body normally has a front wall, a back wall and opposite side walls which define an open upper end. In some cases, the open upper end is closed by compartment doors. Although the design of the bottoms of hopper cars varies considerably, the hopper body usually has a plurality of funnel-shaped hopper bottom portions, each of which has one or more discharge doors or covers selectively closing a discharge opening. The doors selectively close the discharge openings so that the material, such as coal or the like, contained in the hopper car may be discharged therethrough. Many prior art railroad hopper cars utilize various mechanical means for opening and closing the discharge doors but, to applicant's knowledge, those prior art devices are cumbersome to use and are not safe to use. Further, it is not believed that the locking means for ensuring that the discharge doors remain positively closed during transport are as fail-safe as they should be. For example, some of the prior art devices which include an air cylinder means for opening the discharge door or doors could possibly suffer inadvertent opening of the discharge doors if the air pressure in the air cylinders is lost. Further, those air powered systems of the prior art which are installed on the hopper cars during the initial manufacture thereof do not lend themselves to retrofitting existing hopper cars.